<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script src="../js/jquery-3.6.0.js" type="text/javascript" charset="utf-8"></script>
		<style type="text/css">
			#div1{
				width: 200px;
				height: 200px;
				background-color: #FFA500;
/* 				display: none;

 */			
/* 				opacity: 0; */
				visibility: hidden; 

			}
			#div2{
				width: 200px;
				height: 200px;
				background-color: #000000;
				border-radius: 94px;
				background: #FFA500;
				box-shadow:  20px 20px 60px #bebebe,
				             -20px -20px 60px #ffffff;
			}
		</style>
	</head>
	<body>
		<input type="" name="" id="input" value="" />
		<button type="button" id="yz" onclick="yz()">数字验证</button>
		<div id="div2">
		<button type="button">正面</button>
		</div>
		<script type="text/javascript">
			var s = document.getElementById('div2');
			s.onclick = function(){
				s.innerHTML = '反面';
				
			}
			$(document).ready(function(){
				$('#div2').on('click',function(){
					$('#div2').css('background','#f00');
					
				});
				
			});
			function yz(){
				var x = document.getElementById("yz").value;
				if(x == "" || isNaN(x)){
					alert("不是数字");
				}
			}
			
		</script>
	</body>
</html>
